This invention relates to wire-winding apparatuses used, among others, in the field of electrical and electronic component manufacture; and more particularly, to wire tension regulating devices.
The manufacture of transformers, chokes, wire-resistors, solenoids and other forms of inductive components requires a supply of electric wire from a supply spool at a constant pulling tension regardless of variations in the winding speed. The miniaturization of components call for the use of extremely fine wires while ever-increasing winding speed are sought in order to reduce production time and cost. In order to maintain the regularity and evenness of the winding, the tension of the wire must be kept constant regardless of the acceleration and deceleration of the winding equipment and the fluctuation in the diameter of the component being wound.
The prior art has provided various types of mechanical wire tension regulators consisting essentially of a modulable brake applied to the wire-feeding spool and controlled by a mechanical linkage to a tension-sensing lever mounting pulley engaging the wire. The inertia inherent to such a mechanical system causes a brake lag that results in slackening of the wire during deceleration, or sudden tension during acceleration of the winding process. The former can lead to irregularity in the winding sequences. The latter can cause a fracture, or a stretching of the wire that can compromise the accuracy of the wound electrical component.
The principal and secondary objects of this invention are to provide a tension-regulated wire-feeding apparatus suitable for the manufacture of transformers, chokes, resistors, solenoids and other inductance components at a high winding speed using a relatively thin conducting wire where the tension of the wire is precisely regulated during acceleration and deceleration phases at the beginning and end of the component manufacture as well as changes in the radius of the feeding spool or the wound component.
These and other valuable objects are achieved by applying an electronic negative feed-back signal to a magnetic particle brake acting upon the wire supply spool. The feed-back signal of very low hysteresis and a negligible inertia is generated by a current supply modulated by the output of a potentiometer coupled to a wire tension-sensing oscillating arm.